900 (number)
From Halbeeg, the open encyclopedia · Af-Soomaali
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900 is a natural number in the standard numeral system. It comes after 899 and before 901. In Somali it is pronounced "sagaal boqol", meaning 9 times 100.
In the decimal numeral system, 900 is written with three digits: a 9 in the hundreds place, and 0 in both the tens and ones places. In Roman numerals it is represented as CM.
Mathematical properties
900 is a composite number, having divisors other than 1 and itself. Its prime factorization is 2² × 3² × 5², which equals 4 × 9 × 25. Since each prime factor has an even exponent, 900 is a perfect square: 30 × 30 = 900.
900 is also the sum of interior angles of a seven-sided polygon: the formula (n − 2) × 180 with n = 7 yields 900 degrees, the sum of the interior angles of a heptagon. The sum of the integers from 1 to 900 is 405,450.
General use
900 is used as a marker for large round numbers in business mathematics, measurement, and history. The year 900 CE fell within the tenth century. The phrase "sagaal boqol" also appears in the names of certain telephone service codes in many countries.